title: Liposomes with double-stranded DNA anchoring the bilayer to a hydrogel core.
abstract: Liposomes are important biomolecular nanostructures for handling membrane-associated molecules in the lab and delivering drugs in the clinic. In addition to their biomedical applications, they have been widely used as model cell membranes in biophysical studies. Here we present a liposome-based model membrane that mimics the attachment of membrane-resident molecules to the cytoskeleton. To facilitate this attachment, we have developed a lipid-based hybrid nanostructure in which the liposome bilayer membrane is covalently anchored to a biocompatible poly(ethylene) glycol (PEG) hydrogel core using short double-stranded DNA (dsDNA) linkers. The dsDNA linkers connect cholesterol groups that reside in the bilayer to vinyl groups that are incorporated in the cross-linked hydrogel backbone. Size exclusion chromatography (SEC) of intact and surfactant-treated nanoparticles confirms the formation of anchored hydrogel structures. Transmission electron microscopy (TEM) shows ~100 nm nanoparticles even after removal of unanchored phospholipids. The location of dsDNA groups at the hydrogel-bilayer interface is confirmed with a fluorescence assay. Using DNA as a linker between the bilayer and a hydrogel core allows for temperature-dependent release of the anchoring interaction, produces polymer nanogels with addressible hybridization sites on their surface, and provides a prototype structure for potential future oligonucleotide drug delivery applications.
authors.affiliation: Mork Family Department of Chemical Engineering and Materials Science, University of Southern California , Los Angeles, California 90089, United States.
authors.forename: Yasaman
authors.initials: Y
authors.lastname: Dayani
authors.forename: Noah
authors.initials: N
authors.lastname: Malmstadt
mesh_terms: D004247:DNA / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D013499:Surface Properties
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D004247:DNA